Oscillations in deformation properties of heavy rare-earth nuclei

In the framework of relativistic mean-field theory, we study the structural properties of Yb and Hf isotopes over a wide mass range. We find an oscillatory nature of hexadecapole moments from positive to negative, and from negative to positive values, again with an increase of mass number in an isotopic chain. A quadrupole shape change from prolate to oblate shape is predicted in our calculations. For each isotope, a low-lying intrinsic excited state of an opposite quadrupole deformation is noticed. The trends in rms charge radii are studied. (author)